1. Field of the Invention
The present invention relates to a cap removing apparatus, which corrects the posture of a knob of a cap that closes an opening end of a container, such as a test tube containing a sample, and thereafter removes the cap from the container.
2. Description of the Related Art
A conventional cap removing apparatus, disclosed in Japanese Patent No. 2731729, automatically removes a cap from an opening end of a test tube. This conventional cap removing apparatus comprises a test tube holder, a belt conveyor, a rotary driving mechanism, a correcting mechanism and a cap-removing mechanism.
The test tube holder holds a test tube with its opening end closed by a cap, so that the test tube is rotatable in a circumferential direction. The belt conveyor conveys the test tube held in the test tube holder. The belt conveyor has a tube-positioning position and a cap-removing position, which is provided at a predetermined distance from the tube-positioning position.
The rotary driving mechanism is provided in the tube-positioning position. The rotary driving mechanism rotates the test tube held in the test tube holder in the circumferential direction. The correcting mechanism corrects the position of the test tube rotated by the rotary driving mechanism, and corrects the posture of the knob of the cap, which has closed the opening end of the test tube.
The cap-removing mechanism is provided in the cap-removing position. The cap-removing mechanism pinches the knob of the cap whose posture has been corrected by the correcting mechanism, and removes the cap from the test tube. As a result, the opening end of the test tube is opened.
In the conventional cap removing apparatus described above, the test tube, the position of which has been corrected at the tube-positioning position, is conveyed together with the test tube holder to the cap-removing position by the belt conveyor. The cap, which has closed the opening end of the test tube, is removed from the test tube by the cap-removing mechanism in the cap removing position.
The test tube may circumferentially rotate while it is being transferred from the tube-positioning position to the cap-removing position. Accordingly, the knob of the cap may be deviated from the predetermined position at which the cap can be removed from the test tube in the tube-positioning position. In this case, therefore, in the conventional cap removing apparatus, the cap-removing mechanism cannot pinch the knob of the cap.
Further, in the conventional cap removing apparatus, the test tube is conveyed from the tube-positioning position to the cap-removing position by the belt conveyor, which is intermittently operated. Therefore, a time period between correcting the posture of the cap and removing the cap from the test tube is liable to be long.